textproduct: Quad Cities

KEY MESSAGES

- Clear and calm tonight, with a dry and milder day expected on Thursday with high temperatures in the 70s.

- High temperatures warm into the 80s Friday through at least Monday. Humidity levels will also be on the increase through the weekend and into early next week.

- Thunderstorms return to the forecast Thursday night through Tuesday. The Storm Prediction Center has highlighted portions of the area in a marginal, or level 1 of 5 risk, for severe thunderstorms Thursday night and Friday night. Then for this weekend and Monday in a Slight, or level 2 out of 5 risk, for severe thunderstorms.

- At this time, the most widespread and significant severe thunderstorm risk is forecast to be on Monday, followed by Sunday and Sunday night. Stay tuned in the coming days as more details emerge on this severe weather potential.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 124 PM CDT Wed May 13 2026

Dry high pressure will build across eastern Iowa and western Illinois into tonight. Breezy north-northwest winds on its eastern periphery with gusts to around 25-30 mph will continue this afternoon, decreasing with sunset. With calm winds and good radiational cooling overnight, low temperatures will fall into the lower 40s Thursday morning, with a few readings in the upper 30s not out of the question.

It will be mostly sunny to start the day on Thursday, with increasing clouds through the day. With southerly winds, high temperatures will warm into the 70s areawide. With low level warm air advection and a few impulses embedded in zonal flow south of deep low pressure in Canada, scattered rain showers with a few thunderstorms are forecast Thursday night. Severe weather is not expected.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 124 PM CDT Wed May 13 2026

The global ensembles favor zonal flow aloft becoming southwest flow this weekend into early next week as an upper level trough deepens across the Intermountain West. With Gulf moisture return, this will set the stage for multiple rounds of thunderstorms. Surface dewpoints are forecast to increase into the mid 50s F by Saturday and at least into the 60s by Sunday and potentially the lower 70s by Monday. When combined with increasing temperatures into the 80s, buoyancy will also be on the increase across the region, especially Sunday into Monday.

SPC has portions of the regional outlooked in Marginal to Slight Risks from Friday through Monday. Within this period, Monday has the more significant threat for all severe weather hazards (large hail, damaging wind and tornadoes), followed by Sunday afternoon into Sunday night.

From a setup standpoint, a cold front is forecast to stall out across the Upper Mississippi Valley Friday night into Saturday, and then begin to lift north on Sunday as a warm front with a large warm and buoyant sector establishing itself across much of the central US on Monday. Buoyancy will build to the south of this stalled turned stationary turned warm front. The best chance for thunderstorms Friday into Saturday looks to be south of I-80, south of the stalled front. There is some question as to the strength of forcing and shear for thunderstorm coverage and organization, and the SPC Marginal Risk for the southern portions of the area describes the threat well for Friday night, with a small area of a Day 4 Slight risk across the south on Saturday into Saturday night.

Buoyancy continues to build into Sunday. As stronger impulses embedded in southwest flow aloft arrive and the low level jet strengthens Sunday evening and night, the coverage and organization of storms will be greater than compared to Saturday. Monday poses the more significant severe thunderstorm threat from a coverage and organization standpoint with a higher ceiling for all hazard magnitudes for large hail, damaging wind and tornadoes. As low pressure propagates into the Upper Midwest on Monday, with strong mid and low level jets, forcing and shear will be maximized coincident with moderate to strong buoyancy. Specific details and timing will be worked out over the coming days, however, machine learning severe probabilities all point to Monday being the most significant day for severe thunderstorms.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1211 PM CDT Wed May 13 2026

VFR conditions will continue across eastern Iowa and western Illinois for the 18Z TAF cycle. Breezy north to northwest winds with gusts of 20-25kts will continue through early evening. Scattered cumulus in the 3500-4500 ft AGL range will also continue through sunset near the Mississippi River and points east. Winds turn to the south on Thursday, sustained at 8-14kts with gusts to 20 kts.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.